1. Field of the Invention
The present invention concerns novel fluorine-containing diamines as well as polyamides and polyimides prepared from the diamines. The compounds disclosed are useful in the formation of moisture resistant films, fibers and other shaped articles.
2. Technical Background
Fluorine-containing diamines, polyimides and polyamides are well-known in the art; examples can be found in a review article (Cassidy, P. E.; Aminabhavi, T. M.; Farley, J. M. J., Macromol. Sci., Rev. Macromol. Chem. Phys., C29, 365 (1989)) and other recent references.
Rogers, H. G.; Gaudiana, R. A.; Hollinsed, W. C.; Kalyanaraman, P. S.; Manello, J. S.; McGowan, C.; Minns, R. A.; Sahatjian, R., Macromolecules, 18, 1058-1068 (1985), disclose 2,2'-trifluoromethylbenzidine and polyamides.
Harris, F. W.; Hsu, S. L.-C.; Tso, C. C., Polym. Preprints, 31 (1), 342 (1990) disclose polyimides.
WO 91/01340, published on Feb. 7, 1991, discloses diamines of the below formula: ##STR1## wherein each A is a substituent other than H, each Z is a H or substituent other than H and each P is an integer having a value 1 to 3, said A and Z being present in sufficient amount to provide said diamine with a noncoplanar molecular structure.
Japanese Kokai Patent Application No. SHO 62 [1987]-280257 discloses a low-viscosity varnish, which can form a low-thermal expansion resin material when treated by heating.
Japanese Kokai Patent SHO 62 [1987]-176135 concerns an etching method for etching resin film having a low thermal expansion coefficient, using polyimide resin materials.